A number of different techniques have been developed and used for converting a solid cleaning composition into a concentrated cleaning solution. Such wash chemicals include detergents, rinse aids, and the like. The solid detergent product may be contained within a capsule, with only a portion of the detergent block being dissolved with each cycle. The detergent is dissolved by the impingement of a diluent upon the detergent block, the diluent typically being water. The concentrated detergent solution formed by the action of the water falls by gravity into an underlying reservoir, or is directed by a conduit to the wash tank of the washing apparatus.
Utilization of solid cleaning compositions has several advantages over the use of pre-mixed liquid cleaning compositions. These advantages include the fact that the solid detergent is easier and cheaper to ship due to its greatly-reduced weight; the solid detergent requires less storage space; and the solid detergent allows for a safe work environment by reducing possible splashing of hazardous chemicals. Overall, the solid detergent is more convenient for the user, and it permits easy transfer from a container to a dispenser, involving no pouring, spilling or leftover product.
Often, an appropriate amount of new cleaning solution is created for each cleaning cycle. Alternatively, a solid detergent dispenser may utilize a "surge" or reservoir compartment to hold the concentrated solution. The reservoir compartment holds enough concentrated solution for a plurality of machine cycles, with the time between cycles varying greatly depending upon the user's particular demands. That is, the reservoir compartment may be completely emptied and refilled repeatedly during the day, with a cycle occurring as often as every two minutes, or the filled reservoir compartment may sit unused overnight.
The problem with such a reservoir system is that the cleaning solution within the reservoir tends to develop stratification or concentration gradients. More specifically, the detergent concentration near the bottom of the reservoir may be, for example, approximately 25%-40%, with the concentration in the upper part of the reservoir being 6%-11%. This stratification may result from several factors, including an uneven dissolution rate of the solid detergent, a lack of turbulence in the reservoir, and/or a continual drip of the solid cleaning product into the sump after the dispensing cycle has been completed.
The cleaning solution is typically withdrawn from the bottom of the reservoir and is therefore the most concentrated product. Consequently, the concentration of the withdrawn cleaning solution is often too high. The dispensing system's pump, flow lines, and flow control components such as valves may become clogged and inoperable. Even if the clogging problem is avoided, there is a waste of the cleaning product, which can prove costly for the user. Overuse of the product also results in less than optimal cleaning capabilities, because an improper amount of detergent is being dispensed.
The present invention addresses these and many other problems associated with currently available dispensers.
As used herein, the term "utilization point," when used in combination with a wash chemical solution, refers to the place where the solution is used, such as a wash tank, a rinse spray nozzle, a pressurized water line, etc.
As used herein, the term "wash chemical" refers to those chemical components or chemical mixtures commonly added to aqueous liquids present in the machine washing units to aid in the cleaning and rinsing of fabrics and wares. Such wash chemicals include detergents, softeners, bleaches, rinse aids, etc.